ABSTRACT
Initially described by Pringle in 1985, lichen planopilaris (LPP) is a follicular variant of lichen planus and the most common cause of primary lymphocytic cicatricial alopecia. It is characterized by an autoimmune reactive lymphocytic chronic destruction of the hair follicle and successive scarring alopecia of the scalp. In addition to classic LPP, there are three clinical variants of LPP: Frontal fibrosing alopecia (FFA), fibrosing alopecia in a pattern distribution and Graham-Little-Piccardi-Lassueur syndrome. The pathogenesis of LPP is still unclear. It is believed that LPP is a cell-mediated immune condition case in which activated T-lymphocytes target follicular antigens. LPP is characterized by atrophic or scarring patches on the scalp with complete loss of follicular orifices. Trichoscopy is useful for diagnosis and to guide biopsy site selection. FFA is a clinical variant of LPP that affects mainly postmenopausal women and is clinically defined as a progressive recession of the frontal and parietal hairline with skin atrophy.
